Casio Advanced Scientific Calculator FX-991EX


Was £29.99

Now £23.99 inc VAT

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Delivery options available:
  • Free home delivery over £40
  • Free Click & Collect
  • Standard delivery up to 3 working days
  • Next day delivery
  • Named day delivery
  • Saturday delivery


This Casio advanced calculator is allowed in EVERY exam where a scientific calculator can be used.

With 550 functions including spreadsheet calculations for the first time on a calculator this is a must for education.

This calculator is for use in the new core AS and A-Level examinations. 

Ideal for use when studying for GCSEs and above.

. 550 Functions including a spreadsheet function that allows the user to carry out basic spreadsheet calculations for the first time on a scientific calculator

. Icon Menu / 4 x 4 Matrices / Vector, Integration, Differential calculations / 24 parentheses level / Automatic Parenthesis / Variable memory (9) / Exponential, Root calculations / Hyperbolic and invers hyperbolic functions / trigonometric and invers trigonometric functions / 47 scientific constants / Base-N calculations / calculations with technical symbols / Prime factorization / Random Integer

. Large high resolution Display

. Stylish carbon fibre look casing with metallic keys and protective hard case

. Solar powered with battery backup - ideal for exam environments

. 3 year guarantee

Enjoy FREE Next Day courier delivery on all orders over £40 (inc VAT)

For orders under £40, delivery is just…

Standard £3.50

Next Working Day £4.95

Store Delivery FREE

Next Working Day £4.95

Store Delivery FREE

Named Day £6.95

Saturday Delivery £8.95

Delivery is FREE to a Ryman Store of your choice for delivery within 7 working days.

The Extras You Need to Know…

For Next Working Day Delivery orders must be received by 6pm to guarantee next day delivery.

Some of our products are sent directly from our suppliers, and can take a little longer to arrive. Look out for the van symbol next to the product image and the delivery advisory in the product description to easily identify these products.

If you’re outside of England, Scotland and Wales, your delivery prices may change a little. See our complete Delivery Policy here for more information.

If you still have questions, our Customer Services Team would love to hear from you. Just call 0333 103 0901.


Think you might change your mind?

Don’t worry! If you change your mind for any reason or in the rare event there is a fault with your product we are more than happy to offer you a full refund*.

Simply ensure the goods are returned within 28 days of delivery and in a re-saleable condition and we’ll take care of the rest.

*For our full returns policies please see our General Policy.

If you still have questions, our Customer Services Team will be happy to help. Just call them on 0333 103 0901

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You as a customer is our focus and personally delivering the best service is our goal, aiming to offer an unrivalled shopping experience both on-line and instore. Don’t worry if you need to change or cancel your order, here at Ryman we have a speedy returns process at just 72 hours of receipt!

We pride ourselves on our continued commitment to quality, value, reliability and service. With our dedicated Customer Service team available from 8am through to 8pm Monday to Friday and 9am to 5pm over the weekend you can be confident we are here for you.

Such high regard for customer care and specialist knowledge have allowed Ryman to build and retain a very loyal and happy customer base, so whether you’re a new customer or you’ve come back to see us you can Rely on Ryman to welcome you on board.


Need some help?

Our customer services team would love to hear from you if you need help with some product advice or have any other query, please call 0333 103 0901. Overseas please call 00441270442900 (9am to 7pm Monday to Friday, 9am to 5pm Saturdays)

For high street store related queries please contact your nearest store. Please use our store finder for contact details or call our branch liaison team on 01270 530650 (8am to 6.30pm Monday to Friday)

For Business Account enquiries please email [email protected] or call 01270 530635 (8:30am to 5:00pm Monday to Friday, 9am to 6pm Saturdays and 10am to 4pm on Sundays)

Ratings & Reviews


47 Reviews

5.0 / 5 Quality

4.8 / 5 Value

Rating snapshot
  • 5 / 5Quality

    5 / 5Value

    07 July 2019

    Fantastic entry level scientific calculator

    Will give years of use and still be practical into university exams for undergraduates. Has loads of features but not quite as good as the FX-9750GII for obvious reasons. The QR code fair is such a twist of tech genius to help students learn how to write equations and functions while being taught difficult subjects like mathematics and physics. The feature for solving equations with Newton-Raphson method really saves time in exam situations and kitchens the memory burden of users to deliver less errors in result than manual methods. The ability to use spreadsheets is great but there is no way to store data permanently on the calculator. When it powers down, data is lost. I find this annoying as it is solar powered and therefore having the option to disable power saving unabashedly is remiss on Casio's design team. We have unlimited free solar power, let's limit its use! Why? Why? Why? I'm glad I bought this device. Well worth the expense but don't forget the student discount card!

  • 5 / 5Quality

    5 / 5Value

    17 March 2019

    Great Service

    I order this calculator and it only took a few days to receive it. The quality is greater than the way I thought plus the price is amazing.

  • 5 / 5Quality

    3 / 5Value

    17 February 2019


    I bought this last month and this is the best calculator for a level maths and Ryman's click and collect service is super fast and I collected it and next day.

  • 5 / 5Quality

    5 / 5Value

    10 February 2019

    Great features

    I son is so happy using this type of calculator for A Level work

  • 5 / 5Quality

    5 / 5Value

    08 December 2018

    Casio Advanced Scientific Calculator

    I bought this caluclator from Ryman for my son who is doing his A levels .I saw this online on a reduced price. He uses it everyday and has no issues. Thanks to Ryman for the discount

  • 5 / 5Quality

    5 / 5Value

    26 November 2018


    Bought this recently very happy with the purchase. I strongly recommend this item

  • 5 / 5Quality

    5 / 5Value

    26 November 2018

    Does the job!

    Bought for my son who is studying A level maths. Excellent and easy to use . Good price at Ryman’s !

  • 5 / 5Quality

    5 / 5Value

    25 November 2018

    Good product

    Perfect for my needs; straightforward to use. Excellent value for money.

  • 5 / 5Quality

    5 / 5Value

    20 November 2018

    Excellent For A level Maths

    This is a great product to buy if you're doing A level maths. Very helpful and has excellent features. I definitely recommend this product

  • 5 / 5Quality

    5 / 5Value

    15 November 2018


    needed and great for a level maths Allows you to do loads of things like put in quadratics etc.